scholarly journals d2 Law and Penetration Length of Jatropha and Camelina Bio-Synthetic Paraffinic Kerosene Spray Characteristics at Take-Off, Top of Climb and Cruise

Aerospace ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 249
Author(s):  
Sim Sing Mei ◽  
Aslina Anjang Ab Rahman ◽  
Mohd Shukur Zainol Abidin ◽  
Nurul Musfirah Mazlan
Keyword(s):  
Fuel Consumption ◽  
Combustion Temperature ◽  
Early Stage ◽  
Combustion Process ◽  
Operating Conditions ◽  
Fuel Properties ◽  
Spray Characteristics ◽  
Penetration Length ◽  
Ansys Fluent ◽  
Two Phases

A comparison of d2 law and penetration length of biofuels with Jet–A through the incorporation of fuel properties and actual combustor inlet data at various flight trajectories is presented. This study aims to identify fuel properties and flight operating conditions that most influence droplet characteristics accurately. The study comprises two phases involving a simulation using GSP to predict combustor inlet data for the respective flight operating conditions and a simulation using ANSYS Fluent V18.1 to obtain combustion characteristics of biofuels and Jet–A . The biofuels chosen in this study are Jatropha Bio-synthetic Paraffinic Kerosene (JSPK) and Camelina Bio-synthetic Paraffinic Kerosene (CSPK), evaluated as pure (100%) and blend (50%) with Jet–A. Thrust specific fuel consumption (TSFC) of biofuels is improved due to lower fuel consumed by the engine. The d2 law curve shows a heat-up period that takes place at the early stage of the combustion process. The penetration length of the fuels is shorter at take-off. Combusting biofuels reduce combustion temperature and the penetration length of the droplet.

scholarly journals Individual Cylinder Combustion Optimization to Improve Performance and Fuel Consumption of a Small Turbocharged SI Engine

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5548
Author(s):  
Luca Marchitto ◽  
Cinzia Tornatore ◽  
Luigi Teodosio
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Exhaust Emission ◽  
Cycle Variation ◽  
Spark Timing ◽  
Experimental Findings

Stringent exhaust emission and fuel consumption regulations impose the need for new solutions for further development of internal combustion engines. With this in mind, a refined control of the combustion process in each cylinder can represent a useful and affordable way to limit cycle-to-cycle and cylinder-to-cylinder variation reducing CO2 emission. In this paper, a twin-cylinder turbocharged Port Fuel Injection–Spark Ignition engine is experimentally and numerically characterized under different operating conditions in order to investigate the influence of cycle-to-cycle variation and cylinder-to-cylinder variability on the combustion and performance. Significant differences in the combustion behavior between cylinders were found, mainly due to a non-uniform effective in-cylinder air/fuel (A/F) ratio. For each cylinder, the coefficients of variation (CoVs) of selected combustion parameters are used to quantify the cyclic dispersion. Experimental-derived CoV correlations representative of the engine behavior are developed, validated against the measurements in various speed/load points and then coupled to an advanced 1D model of the whole engine. The latter is employed to reproduce the experimental findings, taking into account the effects of cycle-to-cycle variation. Once validated, the whole model is applied to optimize single cylinder operation, mainly acting on the spark timing and fuel injection, with the aim to reduce the specific fuel consumption and cyclic dispersion.

scholarly journals CFD 3D Analysis of Charge Motion and Combustion in a Spark-Ignition Internal Combustion Engine under Close-to-Idle Condition

2020 ◽  
Vol 197 ◽  
pp. 06011
Author(s):  
Roberto Bozza ◽  
Vincenzo De Bellis ◽  
Stefano Fantoni ◽  
Donato Colangelo
Keyword(s):  
Combustion Engine ◽  
Early Stage ◽  
Local Level ◽  
Combustion Process ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Transport Sector ◽  
3D Analysis ◽  
Charge Motion ◽  
Throttle Valve

The increasingly stringent limitations on noxious missions of transport sector highly affect the development of new engines. The operating conditions of the engine at low-load and idle play a relevant role along the regulatory homologation cycles, contributing to overall emissions. In this work, the effectiveness of some solutions to improve the behaviour under close-to-idle operation of a Spark-Ignition motorcycle engine are compared by 3D CFD analyses. Specifically, the effects of two designs of the intake port and of the opening direction of the throttle valve, either clockwise or counterclockwise, are investigated. Multi-cycle simulations are carried out, under motored and fired conditions, for a single close-to-idle operating point. The various designs are compared in terms of capability to generate a stable tumble vortex during the intake phase and to produce an adequate turbulence level at the beginning of the combustion process. The analyses revealed that a clockwise throttle opening can produce enhanced turbulence levels at the end of the compression stroke, especially in a close-to-spark region (increase of about 5% and 27 % at the TDC at a global and local level, respectively, compared to the base configuration). Additional limited improvements are obtained with the high tumbling design, where, however, a penalty on the maximum power output could emerge. The flow and turbulence motion differences among the tested geometries reflect on combustion development in its early stage, and on its degree of completeness at the exhaust valve opening. A clockwise opening of the throttle valve leads to an increase of the mass fraction burned of 5 percent points, compared to the base configuration.

SPRAY VISUALIZATION OF HYDROTREATED VEGETABLE OIL UNDER SIMULATED DIESEL ENGINE CONDITION

2020 ◽  
Vol 40 (04) ◽  
Author(s):  
VO TAN CHAU
Keyword(s):  
Vegetable Oil ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
Cone Angle ◽  
Injection Pressure ◽  
Fuel Properties ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Penetration Length ◽  
Spray Cone

The diversity of alternative fuels and the corresponding variation in their physical and chemical properties, coupled with simultaneous changes in advanced techniques for CI-engine, needed to improve engine efficiency and emissions. Hydrotreated Vegetable Oil (HVO), seen as a promising substitution for petrol-diesel, and diesel fuel (mixed of 7% palm-biodiesel or B7) were analyzed on fuel properties. Then, the influence of these fuel properties on spray characteristics in constant volume combustion chamber were evaluated under conditions of single hole injector of 200m diameter, injection pressure of 100MPa, constant back pressure of 4.0MPa and energizing time of 2.5ms. The results show that HVO had smaller in viscosity (18.48%), density (5.52%), sulfur content, distillation under T50, T90 and higher in derived cetane index (27.2%), heating value (2.2%), respectively, compared to diesel. Spray characteristics of HVO had the same propensity with diesel fuel. HVO revealed a slightly shorter in penetration length (5%) during fully developed zone, a larger spray cone angle (from 0.2 to 1.1 degree wider in quasi-steady state). Both fuels had a similar maximum spray velocity reaching at 5mm to 10mm from nozzle orifice. Also observed was an increase in spray volume of HVO.

Application of a variable-fidelity hydrodynamic optimization strategy in fuel-efficient ship design

2018 ◽  
Vol 233 (18) ◽  
pp. 6293-6306
Author(s):  
Hassan Zakerdoost ◽  
Hassan Ghassemi
Keyword(s):  
Carbon Dioxide ◽  
Fuel Consumption ◽  
Early Stage ◽  
Carbon Dioxide Emission ◽  
Cost Effective ◽  
Ship Design ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Optimization Strategy ◽  
Variable Fidelity

Now more than ever, the amount of fuel a ship consumes and the amount of carbon dioxide emitted from a ship have attracted many researchers’ attention towards efficient and cost-effective ship designs. Therefore, fuel consumption and carbon dioxide emission reduction are two main targets of almost all industrial and scientific communities. The key scope of this article is to describe an innovative methodology for the variable-fidelity design optimization of a ship’s hull-propeller system under multiple operating conditions in early-stage ship design. Non-uniform rational basis spline technique and the efficient multi-objective evolutionary algorithm based on decomposition are, respectively, used to generate variants of hull-propeller designs and minimize the fuel consumption and carbon dioxide emission as objective functions of the proposed problem. The variable fidelity numerical solvers are also applied for the hydrodynamic evaluation of the design performance during optimization. Three different specific fuel oil consumption data provided by the engine manufacturers Wartsila, MAN B&W and Caterpillar are used to optimize a medium-sized bulk carrier driven by a well-known propeller as the initial design. The numerical results show an improvement in performance of the optimal hull-propeller designs.

Combustion Characteristics of Stratified Mixture in Lean-Burn LPG Direct-Injection Engine With Spray-Guided Combustion System

2014 ◽  
Author(s):  
Cheolwoong Park ◽  
Seungmook Oh ◽  
Taeyoung Kim ◽  
Heechang Oh ◽  
Choongsik Bae
Keyword(s):  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Economy ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Direct Injection Engine ◽  
Brake Mean Effective Pressure

Today, we are faced with the problems of global warming and fossil fuel depletion, and they have led to the enforcement of new emissions regulations. Direct-injection spark-ignition engines are a very promising technology that can comply with the new regulations. These engines offer the advantages of better fuel economy and lower emissions than conventional port-injection engines. The use of LPG as the fuel reduces carbon emissions because of its vaporization characteristics and the fact that it has lower carbon content than gasoline. An experimental study was carried out to investigate the combustion process and emission characteristics of a 2-liter spray-guided LPG direct-injection engine under lean operating conditions. The engine was operated at a constant speed of 2000 rpm under 0.2-MPa brake mean effective pressure, which corresponds to a common operation point of a passenger vehicle. Combustion stability, which is the most important component of engine performance, is closely related to the operation strategy and it significantly influences the degree of fuel consumption reduction. In order to achieve stable combustion with a stratified LPG mixture, an inter-injection spark ignition (ISI) strategy, which is an alternative control strategy to two-stage injection, was employed. The effects of the compression ratio on fuel economy were also assessed; due to the characteristics of the stratified LPG mixture, the fuel consumption did not reduce when the compression ratio was increased.

Modelling the early stage of spark ignition engine combustion using the KIVA-3V code incorporating an ignition model

2003 ◽  
Vol 4 (3) ◽  
pp. 179-192 ◽  
Author(s):  
L Andreassi ◽  
S Cordiner ◽  
V Rocco
Keyword(s):  
Early Stage ◽  
Combustion Process ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Gasoline Direct Injection ◽  
Combustion Model ◽  
Cylinder Wall ◽  
Predictive Capability ◽  
Wide Range

The evolution of early stages of homogeneous mixture combustion in spark ignition (SI) engines represents a critical period that greatly affects the whole combustion process. A proper description of this critical phase represents a major issue, which could strongly influence the overall model predictive capability (i.e. model ability to reproduce the real engine behaviour for a large range of operating conditions without any major tuning). Such requirements become even more important for the simulation of last-generation gasoline direct injection or lean stratified engines, where ignition could determine the functionality of the engine itself. In this paper, after a detailed analysis of the ignition physical process and its modelling issues, the predictive capability of the KIVA-3V code has been improved by substituting the original ignition procedure with a more detailed kernel evolution model based on the one presented by Herweg and Maly in 1992. The ignition model introduced in a KIVA-3V version already modified by the authors (re-zoning algorithm, combustion and turbulence models, cylinder wall heat transfer, etc.) has then been tested in order to assess its level of accuracy in describing this complex phenomenon, by varying the most critical engine operating conditions and keeping combustion tuning parameters unchanged. After comparing ignition model results with the corresponding ones presented by Herweg and Maly, a specific application of the overall model (KIVA-3V + ignition model + turbulent combustion model) has been made to perform an analysis of a compressed natural gas (CNG) fuelled engine for heavy-duty applications. To this aim, the in-cylinder combustion history and the related processes as the temperature distribution and NOx formation have been calculated and verified with reference to the experimental data measured in a wide range of operating conditions of an IVECO turbocharged engine.

The Effects of Oxygen Enrichment of Combustion Air for Spark-Ignition Engines Using a Thermodynamic Cycle Simulation

2005 ◽  
Author(s):  
Jerald A. Caton
Keyword(s):  
Fuel Consumption ◽  
Oxygen Concentration ◽  
Power Output ◽  
Combustion Process ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Heat Losses ◽  
Operating Conditions ◽  
Cycle Simulation ◽  
Spark Timing

A thermodynamic cycle simulation was used to examine the effects of oxygen enriched combustion air on engine performance for a range of operating conditions and for different sized engines. The use of oxygen enriched combustion air will have a direct effect on the combustion process and on the overall engine thermodynamics. For example, for cases with higher inlet oxygen concentration (and hence less nitrogen dilution), for the same operating conditions, the combustion gas temperatures and engine cylinder heat losses will be higher. In addition, the engine using oxygen enriched combustion air will be smaller than an engine using normal air for the same power output. The major objective of this study was to quantify these expectations for a range of operating conditions. One special feature of a portion of the current study is the constant engine power output by decreasing engine size as the oxygen concentration increased in the combustion air. Results include detail thermodynamic results of temperatures, pressures and properties as functions of the oxygen concentration of the combustion air. Results also include engine performance parameters such as power, torque, fuel consumption, thermal efficiency, and exhaust temperatures. For one comparison, engine performance and fuel consumption were obtained for an equivalence ratio of 1.0, MBT spark timing, and 2500 rpm. For oxygen enriched combustion air with 32% oxygen, equal power output was obtained with 73% of the displaced volume (all else the same). For the higher oxygen case, the brake fuel consumption increased about 11% primarily due to higher heat losses and higher exhaust gas energy which were a consequence of the higher gas temperatures. For the MBT spark timing case, the nitric oxide emissions increased by about 11% as the oxygen concentration increases from 21% to 25%.

scholarly journals Spray Characteristic of Rapid Mixing Jatropha Oil Biodiesel in Burner System

2015 ◽  
Vol 773-774 ◽  
pp. 496-500
Author(s):  
Amir Khalid ◽  
Latip Lambosi ◽  
Mirnah Suardi ◽  
Shahrin Hisham Amirnordin ◽  
Izzuddin Zaman ◽  
...  
Keyword(s):  
Water Content ◽  
Combustion Process ◽  
Spray Angle ◽  
Jatropha Oil ◽  
Spray Characteristics ◽  
Penetration Length ◽  
Spray Penetration ◽  
Equivalent Ratio ◽  
Toxic Emission ◽  
Photography Method

Jatropha Oil (JPO) is an alternative fuel proposed to be used especially for renewable sources and energy efficiency. Its characteristics need further investigation particularly for the use in an external burner system. The aim of this research is to investigate experimentally the spray characteristics of Jatropha oil in premixing injector for burner system. The Jatropha oil was blended with diesel at different ratio; JPO5, JPO10, and JPO15 at water content of W0, W5, W10 and W15. Fuel, water and air are injected in premix injector, causing the spray of these mixtures to produce lower toxic emission during combustion process. The spray angle, spray penetration length and spray area of different fuel-water ratio and equivalent ratio shall be analyzed from images captured using direct photography method with a DSLR camera. The result of the spray image will be further analyzed and compared between the different batches of image captured. It is shown that the effect of equivalent ratio and water content in fuel-water mixtures will give a significant effect on spray characteristics. Addition of water content will increases the viscosity of the mixtures, hence it increases the spray penetration length, spray area and reduce the spray angle.

scholarly journals An Analytical Model of Homogeneous Charge Compression Ignition Engine for Performance Prediction

2014 ◽  
Vol 564 ◽  
pp. 8-12
Author(s):  
A. R. Najihah ◽  
A.A. Nuraini ◽  
Othman Inayatullah
Keyword(s):  
Fuel Consumption ◽  
Engine Speed ◽  
Model Simulation ◽  
Combustion Process ◽  
Operating Conditions ◽  
Compression Ignition Engine ◽  
Combustion Duration ◽  
Wide Range ◽  
Intake Pressure ◽  
And Performance

A zero dimensional thermodynamic model simulation is developed to simulate the combustion characteristics and performance of a four stroke homogeneous compression combustion ignition (HCCI) engine fueled with gasoline. This model which applies the first law of thermodynamics for a closed system is inclusive of empirical model for predicting the important parameters for engine cycles: the combustion timing and mass burnt fraction during the combustion process. The hypothesis is the increasing intake temperature can reduce the combustion duration and the fuel consumption at wide range of equivalence ratio. The intake temperature were increased from 373-433 K with increment of 20 K. The engine was operated over a range of equivalence ratios of 0.2 to 0.5 at constant engine speed of 1200 rpm and intake pressure of 89,950 k Pa. Simulations were performed using Simulink® under different engine operating conditions. Increasing intake temperature allows reducing the combustion duration by 0.99 °CA and 0.26 °CA at equivalence ratios of 0.2 and 0.5, respectively. The brake specific fuel consumption decreases about 6.09%-5.76% at 0.2-0.5 of equivalence ratios. Thus, fuel consumption can be reduced by increasing intake temperature.

scholarly journals INFLUENCE OF MARINE FUEL PROPERTIES ON IGNITION, INJECTION DELAY AND ENERGY EFFICIENCY

Transport ◽  
2021 ◽  
Vol 36 (4) ◽  
pp. 339-353
Author(s):  
Sergejus Lebedevas ◽  
Nadežda Lazareva ◽  
Paulius Rapalis ◽  
Vygintas Daukšys ◽  
Tomas Čepaitis
Keyword(s):  
Energy Efficiency ◽  
Fuel Consumption ◽  
High Speed ◽  
Operating Conditions ◽  
Fuel Properties ◽  
Rational Selection ◽  
Marine Fuel ◽  
Low Speed ◽  
Medium Speed ◽  
Selection Of

According to the International Council on Combustion Engines (CIMAC) and International Maritime Organization (IMO) statistics, the rational selection of Marine Bunker Fuel (MBF) properties is an effective way to improve operating conditions and energy efficiency of all types of marine Diesel Engines (DEs). The publication presents the results of studies on the influence of heavy and distillate MBF properties on the characteristics of different DE types: high-speed (Caterpillar 3512B, MTU 8V 396TB), medium-speed (SKL VDS 48/42, ChN 26.5/31) ir low-speed (MAN B&W 6S60MC). The aim of work is to form a methodological framework for assessing the influence of marine fuel properties on the energy performance of different types of ship power plants. Numerical methods show that in the case of unfavourable selection of the density and viscosity of marine fuels regulated by the standard ISO 8217:2017, the changes in specific fuel consumption be reach up to 10% low-speed, 4…7% medium-speed, and 2…3% high-speed DEs. As the density varies from light grades to 1010 kg/m3, the change in be is 3…4%. At low viscosity, as the density increases to 1030 kg/m3, the low-speed engine comparative fuel consumption increases by 5%. It is recommended not to use fuel with a density >1010 kg/m3 and a viscosity <300…400 mm2/s. Developed solutions for the rational selection of bunkered marine fuel properties for a specific DE model trough the influence of density and viscosity on fuel injection and combustion characteristics based on multiparametric diagrams of relative fuel consumption change.

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